The field of the present invention is braking systems for motorcycles, and more particularly, braking systems of a type equipped with a modulator operable to reduce hydraulic braking pressure in order to avoid wheel lock.
Brake systems for motorcycles are known which perform an antilock function through provision of antilock pressure reduction mechanisms. Such mechanisms have been interposed in brake lines supplying hydraulic braking pressure to front and rear brake cylinders. An electronic control unit controls the operation of such pressure reduction mechanisms. Reference is made to Japanese Patent Application Laid-open No. 140155/84 and its equivalent, British Publication No. 2 134 200B, for example.
In such braking systems, brake cylinders for each of the front and rear wheels together may be interconnected such that they can be actuated by a brake lever and/or brake pedal. Hydraulic braking pressure is supplied to these brake cylinders through a single free line system at the final stage.
In such systems, each of the front and rear brakes may include more than one means, such as pots, for applying a braking force. With such an arrangement, part of the means for applying braking force are actuated by a hydraulic braking pressure generated by a brake lever while the remainder of the means for applying braking force are actuated by a hydraulic braking pressure generated by a brake pedal. In this way, it becomes possible to control the braking forces for the front and rear wheels delicately and minutely. A brake system constructed in the above manner, however, necessitates provision of two antilock pressure reduction mechanisms for each of the front and rear brake cylinders and this results in an increase in the number of parts and the cost and makes the structure complicated.
A braking system not employing antilock modulators has been developed which is capable of braking both the front and rear wheels by operation of either of a first input means operated by a hand operated element and a second input means operated by a foot operated element. The system is designed for both of the front and rear wheels to be controlled by one or both of the first and second input means operated by hand operated and foot operated elements, respectively. The system provides braking force distribution between the front and rear brakes in accordance with respective forces of the input means. Reference is made to copending U.S. patent application Ser. No. 673,209, filed Mar. 20, 1991 and entitled Braking System for Motorcycle, the disclosure of which is incorporated herein by reference.